the box Speaker 12-280/8-W
the box Speaker 12-280/8-W: inexpensive 12″ driver from the Thomann house brand with 3″ voice coil – Thiele-Small parameters from the retailer's datasheet, only Xmax is missing.
Current · Last checked: 2026-11-13
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General data
Link to section “General data”- Type
- Woofer
- Nominal size
- 12″
- Nominal impedance
- 8 Ω Manufacturer
- Minimum impedance
- 8.3 Ω According to the datasheet it is above the nominal impedance of 8 Ω. This is unusual, but it is what the datasheet says. Manufacturer
- Sensitivity
- 95 dB 1 W / 1 m From the Thiele-Small parameters, the measurement software in the same datasheet calculates 93.1 dB (SPLo). Manufacturer
- Frequency range
- 38 Hz – 2,000 Hz Manufacturer
- Voice coil Ø
- 75.6 mm The product page gives a rounded 3″. Manufacturer
- Winding height
- 15.1 mm Manufacturer
- Gap depth
- 10 mm Manufacturer
- Flux density
- 0.68 T Manufacturer
- Magnet
- ferrite
- Weight
- 5.3 kg Manufacturer
- Baffle cut-out Ø
- not available
- Overall diameter
- 310 mm Manufacturer
- Mounting depth
- not available
- Displacement
- not available
- Recommended enclosure volume
- not available
The Thiele-Small parameters come from an impedance measurement with the LMS measurement software, which Thomann reproduces in the datasheet. Whether a single sample or an average was measured and whether the driver had been broken in beforehand is not stated. The datasheet names no standard for the power handling.
The product page has no Thiele-Small parameters, but the datasheet (PDF) linked there does. This makes it possible to simulate the driver; only an Xmax value for excursion limits is missing. The PlanSound PS-Sub112 is a ready-made build plan for exactly this driver.
What can this driver do?
Link to section “What can this driver do?”Simulation from the datasheet values above. The suggestions are calculated, not stated by the manufacturer.
The EBP is above 100 – by the rule of thumb, this points to a vented enclosure (bass reflex). This is based on an EBP of 120.4.
- Net volume
- 51.5 L
- Tuning frequency
- 49.5 Hz
- F3 (−3 dB)
- 46.9 Hz
- F6 (−6 dB)
- 42.4 Hz
- F10 (−10 dB)
- 37.6 Hz
- Sensitivity (2.83 V / 1 m)
- 94.1 dB
- Max. SPL at 46.9 Hz
- 115.6 dB
- Max. SPL at 93.8 Hz
- 118.1 dB
- Ports
- 1 × 160 mm
- Port area for 17 m/s
- 194 cm²
- Max. port velocity
- 16.4 m/s
- Port length
- 35.9 cm
- at 280 W
- Xmax is not known: excursion and maximum SPL cannot be limited.
- Power into 8 Ω (nominal impedance of the wiring).
- Flattest alignment: lowest F3 without the response rising more than 0.25 dB above the passband level or dropping more than 0.5 dB at 2 × F3.
- The 17 m/s limit (about 5 % of the speed of sound) is a common rule of thumb against port noise, not a standard. Rounded port ends allow higher values.
- Lumped-element Thiele/Small model, Half space, 1 m, chamber losses QL 7, Le as a plain inductance, no room influence. At high levels (heating, non-linear Bl and Cms) real results are lower.
Thiele-Small parameters
Link to section “Thiele-Small parameters”Small-signal parameters as stated by the manufacturer. They change with temperature and level.
Plausibility check
Link to section “Plausibility check”We recalculate dependent values from the datasheet. We flag deviations above 3 %.
| Check | Formula | Datasheet | Calculated | Result |
|---|---|---|---|---|
| Qts from Qes and Qms | Qts = Qes · Qms / (Qes + Qms) | 0.304 | 0.304 | consistent |
Power handling
Link to section “Power handling”- Continuous power (standard not stated)280 W
- Peak power1,120 W
Build plans with this driver
Link to section “Build plans with this driver”Sources
Link to section “Sources”-
Tier B · secondary source
the box Speaker 12-280/8-W – Datenblatt mit Thiele-Small-Parametern (PDF)
Thomann GmbH · 14 May 2025 · accessed on 13 November 2026
DocID 283965 (V2) dated 14 May 2025, linked on the product page as “Produktdatenblatt (PDF)”. Page 1 contains the technical data and an impedance measurement with the Thiele-Small parameters derived from it (output of the LMS measurement software with the model curves “SpkrModel” and “DeltaModel”).
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Tier B · secondary source
the box Speaker 12-280/8-W – Produktseite
Thomann GmbH · accessed on 27 September 2026
The retailer’s house brand; there is no separate manufacturer page. The product page itself gives no Thiele-Small parameters but links a datasheet (PDF) that contains them – see src-thomann-thebox-12-280-datenblatt.
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Tier A · primary source
PS-Sub112 – Datenblatt und Bauplan (PDF)
PlanSound GbR · November 2024 (Date from file metadata) · accessed on 13 September 2026
Six pages: technical data, raw measurement, measurements with tops, DSP preset, photo, build plan with parts lists for 15 and 16 mm. Created on 12 November 2024 according to the file metadata.